The integration of microstrip patch antennas with photovoltaics has been proposed for applications in autonomous communication systems for building façades. Full integration was achieved using polycrystalline silicon solar cells as both antenna ground plane and direct current power generation in the same device. This paper provides an overview of the proposed photovoltaic antenna designs and characterises the variation of the electromagnetic properties of the device with temperature and solar radiation. Measurements for both copper and solar antennas are reported on three different commercial laminates with contrasting values for thermal coefficient of the dielectric constant.